One year and nine months old baby with a fever of 39 degrees should be promptly used antipyretic drugs to lower the body temperature, and should also seek medical attention for examination and treatment when high fever occurs repeatedly. A one year and nine months old baby with a fever of 39 degrees, which has exceeded 38.5 degrees, needs to be promptly given fever-reducing medications, such as ibuprofen and acetaminophen, to bring down the child’s body temperature. Because not timely control, the body temperature continues to increase, may lead to febrile convulsions. Drugs to reduce fever at the same time can also be coupled with physical cooling, such as warm water baths or head placement of antipyretic patches. In symptomatic antipyretic at the same time also need to do other care, such as appropriate to the baby drink more water, to ensure adequate body fluids, to prevent dehydration; strengthen the body warmth, to prevent the cold, keep indoor ventilation and so on. There are many reasons why a one-year-old nine-month-old baby has a fever of 39 degrees, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.